An Open Box Is to Be Constructed from a Piece $15$

Essay

An open box is to be constructed from a piece of sheet metal $15$ in by $25$ in by cutting squares of length $x$ from each corner and folding up the sides.
(a) Express the volume $V$ of the box as a function of
$x$ .
(b) What is the domain of $V$ ?
(c) Draw a graph of the function $V$ and use it to estimate the maximum volume for the box.